The present invention relates, in general, to thin-film electroluminescent (TFEL) devices and, more particularly, to multi-colored TFEL devices.
Monochromatic TFEL devices, such as that depicted in Inazaki et al. Pat. No. 3,946,371, are known in the art. These devices typically comprise five layers: an electroluminescent phosphor layer, a pair of insulating layers, and a pair of electrodes. This composition is supported by a transparent substrate such as glass.
These TFEL devices, along with associated power supply, matrix addressing and logic circuitry, are utilized as flat screen display monitors for various applications, such as laptop computers.
Color TFEL devices, such as that depicted in Pat. No. 4,719,385 by Barrow et al., are also known in the art. This device uses a pair of subpanels with two different phosphors to provide displays of two colors and combinations of those colors. In the U.S. Pat. No. 4,719,385, a colored oil, such as red, is used to filter the light emission of one phosphor panel to provide a red color display.
A drawback of the previous color TFEL displays is the requirement that more than one subpanel be used. The use of multiple subpanels greatly increased the size and weight of the displays using these panels. Additional drawbacks to the use of multiple panels are that: more power is required to operate multiple panels than one panel; the brightness of the back subpanels is diminished by the forward subpanels through which its light must pass; and the cost is greater to fabricate multiple panels.
Accordingly, it is an object of the present invention to provide a multi-colored TFEL display which overcomes the above deficiencies.
A further object of the present invention is to provide a multi-colored TFEL display which is fabricated in a single panel.
Another object of the present invention is to provide a multi-colored TFEL display which provides improved brightness.
Still another object of the present invention is to provide a multi-colored TFEL display which is a lower power consuming display.
Yet another object of the present invention is to provide a multi-colored TFEL display which is more economical.
Another object of the present invention is to provide a multi-colored TFEL display with improved red color.
Still another object of the present invention is to provide a multi-colored TFEL display with an improved red color filter.